Sound record



' Jan. 26, 1943. v. L. ROBERTS 2,309,276

SOUND RECORD Filed April 10, 1944 Patented an. 26, 1943 SOUND RECORDVernon L. Roberts, Chicago, 111., assignor of onehalf to Richard H.Wann, Chicago, Ill.

Application April 10, 1941, Serial No. 387,800

Claims.

My invention relates to sound records of the disk type and it is moreespecially concerned with so-called home recordings" as distinguishedfrom commercially produced records.

When making instantaneous sound recordings in the home on the averagenon-professional type recording mechanisms, it is not possible to equipthe recorded disk with the special eccentric end grooves which, oncommercially pressed records, appear after the completion of theconcentric spiral sound grooves.

The purpose oi sucheccentric end or control grooves on commerciallypressed records is to mined distance from the center of the record andothers require a reversal of direction of the stylus or both.

I have provided a novel instantaneous sound recording disk and method ofproducing the same which may conveniently be employed by any unskilledperson in the home on the ordinary home recording machine, whereby sucha disk may be equipped with an eccentric control groove, thus permittingit to be used on automatic record changing and record stopping devicesin the same manner as commercially pressed records- I accomplish thisresult in the following manner. The blank record as sold to theconsumer, instead of being provided only with the central hole toreceive the turn table spindle and one or more-other holes ordepressions to receive a driving pin, is in addition provided with anoil center hole of about the same size as the center spindle hole. Theuser, when ready to record, places the disk on the turn table in theusual manner with the spindle extending through the central hole andproceeds to make his recording in the usual way, producing a spiralgroove beginning adjacent the periphery of the disk and extending tosome point intermediate the center and the periphery. The user thenremoves the record from the spindle and replaces it thereon,

this time inserting the spindle through the off on the record and seatedat or near the inner end or the sound groove and the turn table againset in motion. The stylus will then cut a substantially circular groovein the record, but this groove will naturally be eccentric with respectto the center hole, since the rotation is on an off center axis.Obviously, when such a record is played in the usual manner, thereproducer, after traversing the sound groove. will then enter theeccentric groove and will immediately be swung sharply to a point nearerthe center of the disk and will then be swung outwardly, i. e., in areverse direction, as it continues to traverse the eccentric groove.Such amovement of thereproducer arm will operate either of the two typesof stops commonly used. Thus, if a limit stop is employed, it will beactuated by the time the reproducer reaches the innermost point on theeccentric groove. On the other hand, if the reverse movement stop is inuse, it will be tripped when the reproducer, after having reached theinnermost point on the eccentric groove, is swung outwardly toward thesound groove.

The accompanying drawing illustrates a record made in accordance with myinvention.

In the drawing, numeral I0 represents a disk which, as sold to theconsumer, is provided with a central aperture l2 and an oil center holel5,

and may also have one or more holes I6 or other deformation to cooperatewith a.drive pin or like element for preventing slippage between recordand turn table. By placing the hole 15 as close as possible to thecenter hole l2, a sound groove of maximum length may be cutif desired.The numeral 20 represents the sound groove cut in the record by theconsumer on his sound recording machine while the center hole I! isengaged on the spindle or the turn table. After completion of the soundgroove 20 the disk is removed from the spindle and replaced with the oilcenter hole i5 engaging the spindle, and the control actuating groove 25is then cut, as explained above, by again putting the turn table intorotation and so adjusting the cutter arm that the control groove 25 willjoin the innermost convolution of the sound spiral 20, and then willextend toward the center, so that, when the record is" played, thereproducer is given an in and out movement by said groove 25.

The oil center'hole l5 and center hole I! are preferably equidistantfrom the drive hole l6 In an embodiment of my invention, the drive holel6 may be employed as the spindle hole 15 for cutting the control groove28, thus reducing the number of perforations in the disk.

The term fcontroi groove as used in the claims reiers to a groove foractuating an automatic stop, record changer, or other automaticmechanism.

Various other changes and modifications coming within the spirit of myinvention may sughence, I do not 'wish to be limited to the specificembodiment shown and described or uses mentioned except to the extentindicated in the appended claims.

I claim:

recording, having a center hole extending therethrough suitable toreceive the spindle of a turntable, a second similar hole disposedrelatively close to said center hole, and a circular control grooveextending from the terminal sound groove position, radially of therecord, to a point intermediate said position and saidlholes.

2; A disk especially suitable for home sound recording, said disk havinga center hole extending therethrough, suitable to receive the spindle ofa turn table, and a second. similar hole disposed at a pointintermediate the center and the innermost convolution of the soundgroove 1. A disk especially adapted for home sound gest themselves tothose skilled in the art, and,

asoaare to be cut thereon, said holes being relatively close together.

3. A sound record especially adapted to home recording comprising a diskhaving a center hole.

suitable to receive the spindle of a turn table, a spiral sound grooveon said disk extending from a point adjacent the periphery to a pointspaced inwardly from the center, asecond spindle receiving holeintermediate the center and the innermost portion of the sound groove,and a control groove formed with the second hole as its axis of rotationand communicating with the innermost portion of the sound groove.

4. A disk especially suitable for home sound recording, said disk havinga center hole extending therethrough, suitable to receive the spindle oia turn table, a second similar hole disposed at a point intermediate thecenter and the innermost convolution of the sound groove to be cutthereon, and a deformation in said disk to accommodate a drivingelement.

5. A disk especially suitable for home sound 'recording, said diskhaving a center hole extend- VERNON L. ROBERTS.

